package com.util;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;


public class VerifyCodeServlet extends HttpServlet {  
    static final long serialVersionUID = 1L;  
  
    public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
        response.setHeader("Pragma", "No-cache");  
        response.setHeader("Cache-Control", "no-cache");  
        response.setDateHeader("Expires", 0);  
        response.setContentType("image/jpeg");           
        //生成随机字串  
        String verifyCode = VerifyCodeUtils.generateVerifyCode(4);  
        //存入会话session  
        HttpSession session = request.getSession(true);  
        session.setAttribute("VerifyCode", verifyCode.toLowerCase());  
        //生成图片  
        int w = 200, h = 80;  
        VerifyCodeUtils.outputImage(w, h, response.getOutputStream(), verifyCode);   
    } 
    
}  
